Welcome to Brewers Rumors: A blog created by columnist Alec Dopp — striving to provide the best Brewers content on the web. Breaking news, interviews, opinions, scouting reports — we've got it all (or at least we like to think so).

What We Learned from Tyler Thornburg’s MLB Debut

After much speculation as to who would take the mound for the Milwaukee Brewers on Tuesday night against the Toronto Blue Jays, it was not-so-formally announcedMonday night that 23-year-old Brewers pitching prospect Tyler Thornburg would take the mound for Ron Roenicke’s bunch against the heavy-hitters from the north.

Thornburg, who at this time last year was still pitching for the Brewers’ class-A minor league affiliate Wisconsin Timber Rattlers, was recalled from double-A to triple-A earlier in the week, and was expected to join the Brewers’ triple-A affiliate Nashville Sounds on Monday. Obviously that wasn’t the case, as the Houston, Texas native made his way to Milwaukee sometime after he had this to say to all of his followers on Twitter early Sunday afternoon.

One of the more impressive prospects in Milwaukee’s system since being drafted in the third round of the 2010 draft, Thornburg has posted some gaudy numbers during his time in the minors, with this year being quite possibly his most dominant go-around yet. In 13 starts with Milwaukee’s double-A affiliate Huntsville Stars, the Charleston Southern product went 8-1 and posted a 3.00 ERA, (3.39 FIP), holding batters to a .203 batting average and .250 BABIP while striking out nearly a batter per inning.

Of course, Thornburg’s highly-anticipated Major League debut at Miller Park on Tuesday night was by no means his most memorable outing of the year, which is to some extent expected given his lack of experience both in the upper-minors as well as his unfamiliarity with big-league hitting.

Your browser does not support iframes.

In 5.1 innings (93 total pitches), Thornburg conceded five earned runs on seven hits allows, striking out two and walking none. He strutted his above-average fastball-changeup combination early on and got through the first five innings relatively unscathed. However, it pretty much unraveled in the sixth innings, when he allowed three consecutive home runs, putting the Brewers behind by a 6-4 mark.

All things considered, there are plenty of positives to take away from Thornburg’s first outing in the majors. At the same time, though, there are a few areas for concern that will need to be addressed once he gets his feet back under him in the minors the rest of this season.

First and foremost, I thought Thornburg commanded his pitches extremely well. A pitcher who’s lowered his walk rate progressively with each season in the minors (4.3 BB/9 in 2010, 3.3 BB/9 in 2011, 2.9 BB/9 thus far in 2012), Thornburg has always been known for having at the very least respectable command on the mound. On Tuesday night, as I alluded to earlier, Thornburg’s command was on point, walking no batters in 5.1 innings of work.

On the flip side of things, it was fairly evident that Thornburg’s go-to pitch was his fastball throughout the contest, and boy did he get his reps in. Of his 93 pitches against the Blue Jays, exactly 63 of them were fastballs, enough to account for a staggering 73 percent of his pitches, according to Brooks Baseball. Furthermore, the Blue Jays were able to tee off on Thornburg’s heater — which topped out a 95.7 MPH and had an average speed of 92.26 MPH — whiffing on just two of his fastball offerings on the night.

Given that Thornburg relied so heavily on his fastball in his first big-league outing, it should come as no surprise that the Blue Jays socked four round-trippers off the young 23-year-old. Whenever a lineup comparable to Toronto’s gets numerous looks at the same pitch, it’s almost a given that they’re going to hit the ball with authority more often than not.

Mechanically speaking, Thornburg looked the part. His notorious Tim Lincecum-esque delivery that we took a look at in early March manifested itself early in Tuesday night’s contest. The chart below displays the release points of Thornburg’s fastball, curveball and changeup (courtesy of Texas Leaguers),

Courtesy of Texas Leaguers

Working over the top with a delivery that looks as though it puts a ton of ware and tare on his arm, one can only expect Thornburg’s release points to deviate a bit. Having said that, I think that his release points were pretty consistent given the heat of the moment in his first big-league start. That will most definitely be a sign of good things to come; the more Thornburg can repeat his delivery, the more effective his fastball-changeup combination will become.

Overall, I thought Thornburg’s first big-league outing warrants a lot of optimism but also a few areas of concern, though nothing worth losing sleep over. It should be interesting to see how he handles his demotion back to triple-A Nashville. If he can produced relative to his career numbers there, I think he’ll push for a permanent bullpen spot by the end of next season.